What Material are the Bypass Valve and Valve Head Made of? January 31, 2025 16:44 Updated They are made of a plastic called Celcon and both products are NSF stamped. Bypass Valve: Valve Head: Related articles How Does a Bypass Valve Work? How Much Resin Should Be in the Tank? Why does my water smell after installing a softener? Morton Product Insert (QR Code) How do you know when it's time to upgrade your softener?